Scoop for cat litter

ABSTRACT

A circular litter box having a scoop removal remounted in a scoop holder which is pushed around the sidewall of the box to scoop the box. The mounting mechanism for the scoop causes the scoop to assume a relatively vertical position during scooping, to minimize formation of a wave of litter in front of the scoop as it is rotated, but causes the scoop to assume a more horizontal position as the scoop is removed, so the collected waste will not spill from the scoop during removal.

PRIOR APPLICATION

This application claims the benefit of U.S. Provisional Application Ser.No. 60/440,354, filed Jan. 16, 2003 entitled “SCOOP FOR CAT LITTER”.

FIELD OF THE INVENTION

This invention relates to an apparatus for guiding a scoop out of acircular litter box such that waste captured by the scoop, does notspill from the scoop, and to other aspects of litter boxes and litterbox scoops.

BACKGROUND OF THE INVENTION

Scoops or sieves are commonly used for capturing and removing waste froma litter box.

Most scoops are handheld and separate from the litter box. Handheldscoops are used to randomly sift through the litter in search of waste.The person performing removes the waste filled scoop manually from thelitter box.

Some scoops are incorporated into a litter box design and are notremovable from the apparatus. The scoop may automatically or semiautomatically move through the litter pushing the waste. U.S. Pat. No.5,226,388 describes a litter box and scooping apparatus where at one endof the litter box the bottom curves upward such that scoop pushes thewaste up the curve until the scoop is horizontal and will hold the wasteindependently. The scoop moves into position above a reservoir and thenrotates down to deposit the waste. In U.S. Pat. No. 4,048,465 the wasteis pushed up the upwardly curved bottom end of the litter box and thenfalls over the edge of the litter box into a storage reservoir.

Other litter boxes that have non-removable scoops include those wherethe scoop is fixed to the bottom of a drum shaped container. When thedrum is rotated the scoop passes through the litter, capturing andretaining the waste while letting the litter pass through. As drumcontinues to rotate the waste is guided to a collection assembly andthen to a waste reservoir. The waste reservoir can then be removed fordiscarding waste. U.S. Pat. No. 5,509,379 describes such a device.

U.S. Pat. No. 5,259,340 describes a device where a scoop rotates withina litter box, having a drum shaped interior, and captures waste as itpasses through the litter. The scoop stops in a secondary position wherewaste may drop into a storage container to enable disposal.

Some scoops are incorporated into litter box design but are removable.U.S. Pat. No. 6,295,949 discloses a litter box where waste is capturedby a scoop when the litter box is rotated ninety degrees into asecondary position. The scoop is then removed from the litter box andthe waste is disposed of.

Other types of scoops include those that rest on the bottom of thelitter box. U.S. Pat. No. 5,823,137 discloses a scoop, which rests onthe bottom of a litter box and is hingedly attached to the upper lip ofone end. This scoop captures waste when lifted upward. As the scoopcontinues upward, the waste slides down the scoop into storagereservoir. The scoop is not intended to be removed during scooping.

Some scoops contain movable features in order to remove waste from thelitter box. U.S. Pat. No. 6,286,459 describes a litter container withrotary movement sieve. A scoop cleans the litter box while verticallyoriented and then is hingedly able to horizontally reposition itself asit is removed from the litter box. In the horizontal orientation, thescoop is able to retain waste as it is removed from the litter box.

As litter box design has changed, so have scoop designs. A circularlitter box with a rotary sieve or scoop requires new methods forinserting, positioning and removing a detachable scoop.

BRIEF SUMMARY OF THE INVENTION

It is an object of the present invention to provide a mechanism suchthat the waste collected by a removable scoop in a circular litter boxdoes not fall out of the scoop as the scoop is removed from the litterbox.

Unlike other litter boxes, a circular litter box presents itself as anendless container to a scoop that is radially rotated in the container.There is no end where the scoop completes its sieving. There is no orfinal removal point.

Additionally, any scoop rotated in the litter box will cause a “wave” oflitter to build in front of the scoop. If this wave is too large someparts of waste can “surf in front and will not enter the scoop.Secondly, the wave could become high enough to disturb and interferewith the mechanism for attaching the scoop to the sidewall. Thirdly, thewave could possibly crest over the litter box. Fourthly, a large wavemay decrease the random spread of litter in the container byagglomerating much of the litter in an area ahead of the scoop.

The size of the wave is determined by several factors. The greater thesurface area of the scoop contacting the litter, the more litter ispushed, and the bigger the wave. The orientation of the scoop is also afactor. If part of the scoop is positioned more horizontally in thelitter, the perforations of the scoop will tend to carry litter alongduring the scooping movement, building up the wave.

Therefore, the optimal position for a scoop sieving the litter containeris a more vertical position. However, in this position the scoop cannotbe lifted directly out of the container without waste spilling from thescoop.

Therefore, it is the object of this invention to present a mechanismthat will guide the movement of a scoop as it is removed from a circularlitter box such that collected waste is less likely to fall out of thescoop.

In one of its aspects the invention provides a circular litter containercomprising: (a) a sidewall; (b) a scoop holder mounted on said sidewallfor travel in a direction of travel around said sidewall; (c) a scoop;(d) a mounting mechanism for removably mounting said scoop on said scoopholder; (e) said mounting mechanism comprising cooperating mountingmeans on said scoop and said scoop holder for said scoop to have anoperating position in which said scoop is oriented at a first anglerelative to said direction of travel in which said scoop may be rotatedthrough litter in said container while minimizing formation of a wave oflitter piled in front of said scoop; (f) said cooperating mounting meansincluding a guide such that as said scoop is removed from said scoopholder, the orientation of said scoop is redirected to a second anglenearer to the horizontal than said first angle, whereby to help retaincollected waste on said scoop: (g) said container having a bottom andsaid scoop holder including a scraper bar mounted to scrape said bottomas said scoop holder is rotated in said container.

In another aspect the invention provides a mounting mechanism having acurved track built into the sidewall slider which guides the movement ofthe scoop in and out of the litter box in a forward and upward motionthereby retaining collected waste in the scoop.

In another aspect, the invention provides for a track built into thescoop unit, which slides along a track slider/pivot built into thesidewall slider. An additional guide track built into the sidewallslider directs the movement of the scoop unit in and out of the circularlitter box such that it will assume forward and upward motion duringscoop removal. Thereby, the waste collected in the scoop does not fallout.

In another aspect of the invention, a straight track is built into thesidewall slider, which guide the scoop out of the litter box in aforward and upward motion. Collected waste is retained in the scoop.

Further objects and aspects of the invention will appear from thefollowing description, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a portion of a litter container showinga scoop carrier according to the invention in position thereon;

FIG. 2 is a view similar to that of FIG. 1 but showing a scoop unitabout to be placed into the scoop carrier;

FIG. 3 is a perspective view similar to that of FIG. 2 but showing thescoop unit nearly in position on the scoop carrier;

FIG. 4 is a perspective view similar to that of FIG. 3 but showing thescoop unit fully in position on the scoop carrier;

FIG. 4A is a perspective view of the scoop carrier of FIGS. 1 to 4;

FIG. 5 is a diagrammatic view of disk units and a guide track for analternative method of mounting a scoop unit on a scoop carrier;

FIG. 6 is a plan view showing the mechanism of FIG. 5 on a scoop carrierin position on a container wall;

FIG. 7 is a view similar to that of FIG. 6 but showing the disks furtherdown the guide track;

FIG. 8 is a sectional view showing an alternative guide track and disksfor mounting a scoop unit on a scoop carrier;

FIG. 9 is a plan view showing the guide track of FIG. 8 in position tobe mounted on a scoop carrier;

FIG. 10 is a view similar to that of FIG. 9, but showing the scoop unitfurther in mounting position on the scoop carrier;

FIG. 11 is a plan view similar to that of FIG. 10, but showing the guidetrack for the scoop unit fully mounted in position on the scoop carrier;

FIG. 12 is a plan view showing another embodiment of a guide track on atrack slider for mounting a scoop unit on a scoop carrier;

FIG. 13 is a plan view similar to that of FIG. 12 showing the guidetrack and track slider fully mounted on the scoop carrier;

FIG. 14 is a perspective view of a scoop and a scoop change piecedetached from the scoop unit;

FIG. 15 is a perspective view of a disposable scoop change piece withcircular perforations;

FIG. 16 is a perspective view of a disposable scoop change piece withslanted perforations;

FIG. 17 shows a handheld scoop, which may be resized;

FIG. 18 shows a mechanism for connecting a different sized sieve to thescoop of FIG. 17;

FIG. 19 is a top plan view of the scoop and a second sized sieve whichcan be connected together;

FIG. 20 is a perspective view the scoop of FIG. 19 after the size of thesieve has been altered;

FIG. 21 is a perspective view of a scoop and litter container suitablefor receiving a cover;

FIG. 22 is a perspective view of the scoop and litter container of FIG.21 with a cover thereon;

FIG. 23 is a perspective view of a portion of the cover of FIG. 22; and

FIG. 24 is a perspective view of the inside of the cover.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference is first made to FIGS. 1 to 4A inclusive, which show a littercontainer 20 according to the invention. The litter container 20 is acircular container having a flat bottom 22 and an upstanding sidewall 24extending in a circle around the bottom 22.

Mounted on the sidewall 24 is a mounting mechanism or scoop carrier 26,which serves to support a scoop unit 28 and to carry the scoop unit 28rotatably around the sidewall 24.

The scoop carrier 26 includes a sidewall slider 30 portion, which mountson the sidewall 24, and a rigid bar 32, which extends radially inwardlyfrom the sidewall slider 30 to approximately the center of the bottom22. The sidewall slider 30 comprises a vertical wall 34 having a curvedportion 36 at its top, which extends radially outwardly and downwardlyto hook over the top edge of the container sidewall 24, to support thescoop carrier 26 on the rim of the container sidewall 24.

Projecting from the upper edge of the top wall of the scoop carrier is apost 38, which serves as a handle to grasp the scoop carrier 26 and torotate it circumferentially around the periphery of the containersidewall 24.

The vertical wall 34 of the scoop carrier 26 includes a socket 40, whichis circular in outline and is molded into the vertical wall of the scoopcarrier 26. The socket 40 is dimensioned to accept a matching male plug42 on the scoop unit 28 as will be described.

At the front upper end of the vertical wall 34 of the scoop carrier 26,there is a radially inwardly projecting, vertically oriented U-shapedchannel 44 (FIG. 4A), which accepts a leading portion of the scoop unit28, as will also be described.

The rigid bar 32, which extends radially inwardly from the bottom of thescoop carrier 26, includes at its radially inner end an opening. A pivotpin 61 extends through the opening and through the bottom of the littercontainer 20 to secure the rigid bar 32 to the flat bottom 22 of thelitter container 20 and to act as a pivot about which the scoop carrier26 rotates when the user grasps the post 38 to rotate the scoop carrier26.

The scoop unit 28 includes a scoop portion 46 preferably formed frommesh having openings of a suitable size for sieving cat litter in thecontainer 20. The scoop portion 46 is concave as viewed from thedirection of its rotation (indicated by arrow 1) in the container 20.

Fixed to the scoop portion 46 is a supporting frame 48 (made for examplefrom metal rods) extending forwardly from the scoop portion 46. The plug42 which is of circular disk shape, will be seen to be located at therear radially outer and upper corner of the junction between thesupporting frame 48 and the scoop portion 46.

At the forward end of the scoop unit 28 there is located a generallyradially oriented handle 50, to which the frame members are secured. Thehandle 50 serves as a handle, which the user may grasp when insertingand removing the scoop unit 28 from the litter container 20.

At the radially outer junction of the supporting frame 48 with thehandle 50 there is located a forwardly extending flange 52 (constitutedby a bent portion of part of the frame). The flange 52 fits into theU-shaped channel 44 as will be described, to help lock the scoop unit 28to the scoop carrier 26.

The rear socket 40 (FIG. 4A) includes a vertical circular wall 54 and acircular flange 56 extending around approximately 180 degrees, having anopening facing forwardly and slightly upwardly. The circular flange 56extends radially inwardly by a width which is slightly greater then thethickness of the plug 42, and when the plug 42 is inserted in the socket40, the radially inner edge 57 of the circular flange 56 covers part ofthe outer circumference of the plug 42, thereby locking the plug 42securely within the socket 40 against sideways movement of the plug 42.The combination of the fit of the plug 42 within the socket 40, and thefit of the flange 52 within the U-shaped channel 44, holds the scoopunit 28 securely but removably to the scoop carrier 26. Flange 56includes drainage openings 59 to allow any litter granules trapped inthe flange 56 to escape.

The mechanism described operates as follows. When the user wishes toinsert the scoop unit 28 into the scoop carrier 26, the user holds thescoop unit 28 by the handle 50 and inserts the plug 42 into the socket40, with the flange 52 located above the U-shaped channel 44. The userthen will move the handle downwardly so that the flange 52 enters theU-shaped channel 44. Continued downward movement of the flange 52 islimited by a bottom wall 58 in the U-shaped channel 44, which functionsas a stop, so that the scoop unit 28 is thus locked securely into thescoop carrier 26.

The user then grasps the post 38 on the scoop carrier 26 and rotates thescoop carrier 26 in the direction of arrow around the sidewall 24. Thiscarries the scoop unit 28 through the litter in the container 20, sothat the scoop portion 46 will sieve the contents of the container 20.

The rigid bar 32 built into the scoop carrier 26 has several uses. Itserves to stop further downward movement of the scoop unit 28 whileproviding support for the scoop portion 46 and scoop unit 28 when inscooping position. It also importantly aids the scoop portion 46 byremoving a portion of the stress that the scoop portion 46 and scoopunit 28 would normally experience if the rigid bar 32 did not exist.When the scoop unit 28 is rotated to scoop the litter container 20, therigid bar 32 will be the first object to encounter litter clumps thathave become stuck to the bottom or side of the litter container 20.Clumps commonly become stuck to the flat bottom 22 when clumping litteris used. As the rigid bar 32 is structurally very durable, and issupported well at both ends, it easily dislodges the stuck clumps. Ifthe rigid bar 32 were absent, the scoop unit 28 would have to be builtmore durably as the scoop portion 46 would have to knock stuck clumpsoff the flat bottom 22. Additionally, the scoop unit 28 could be moreeasily broken as it would only be supported at one end, whereas therigid bar 32 is supported at both ends.

After the scoop unit 28 has been rotated in the litter container 20 tocollect litter clumps, it must be removed from the container 20 foremptying. During removal, the scoop unit 28 follows the reverse motionto that used when it was inserted. When the handle 50 is pulledupwardly, the leading edge 60 of the scoop portion 46 rotates upwardlyand forwardly as the flange 52 is pulled up and out of the U-shapedchannel 44. The forward and upward rotation of the scoop unit 28 keepswaste, which has been pushed onto the scoop portion 46, in position onthe scoop portion 46.

As the handle 50 continues to be pulled upwardly, and as the flange 52emerges from the U-shaped channel 44, the plug 42 moves forwardly andupwardly out of the socket 40. The scoop portion 46 becomes positionedin a generally horizontal position so that the collected clumps cannotfall from the scoop portion 46 (but loose litter granules will fallthrough the openings between the mesh of the scoop portion 46 and willbe returned to the container).

DETAILED DESCRIPTION OF A SECOND EMBODIMENT

Reference is next made to FIGS. 5 to 7, which show a second embodimentof the invention The second embodiment differs from the first embodimentin that the plug and socket 42, 40 and the flange and channel 52, 44 ofthe first embodiment have been removed and been replaced in part by twocircular disks 80 at the radially outer end of the scoop unit 82 whichprovide a two point support for the scoop unit 82 on the scoop carrier84, as will now be described. In addition the rigid bar 32 has beeneliminated in this second embodiment.

In particular the second embodiment includes a guide track 86,consisting of a pair of spaced L-shaped rails 88, which protruderadially inwardly from the inward wall 90 of the scoop carrier 84, andhave outer flanges 92 protruding towards each other. The two circulardisks 80 are secured at vertically spaced locations on the radiallyouter edge of the scoop unit 82 and fit into the guide track 86. The twocircular disks 80 are attached together by a join piece 94 such that theposition of each disk 80 relative to one another cannot change. Eachdisk 80 has an attachment member 96 protruding from its center, whichintegrally connects each disk 80 to the Scoop Unit 82. In the drawingsthe join piece 94 is illustrative and may not be needed, as each disk 80will be fixed in place relative to one another when molded to the sideof the Scoop Unit 82.

FIG. 6 shows the disks 80 of Scoop Unit 82, placed into the top of theguide track 86. As will be apparent from FIG. 6, when the circular disks80 are near the top of the guide track 86, the scoop portion 98 of thescoop unit 82 is held in a generally horizontal position.

As shown in FIG. 7, as the scoop unit 82 is pushed downward, therearward curve of the Guide Track 86 guides the disks 80, and hence theScoop Unit 82, backwards until the scoop portion 98 reaches scoopingposition. At this point a stop member 100 in the middle of the GuideTrack 86 blocks the circular disks 80 and prevents further downward andrearward movement of the scoop unit 82. The Scoop Unit 82 is ready fortravel in the litter container 102.

After scooping and capturing waste, the Scoop Unit 82 is ready forremoval from the litter container 102. The Scoop Unit 82 is pulledupward by its handle 104. The movement and positioning of the scoop Unit82 and the scoop portion 98 is the reverse of when inserted into theguide track 86. The scoop portion 98 moves forward against the litterand upward therefore retaining the captured waste within the scoopportion 98.

In this embodiment a rigid bar 32 is not shown in order to simplify theillustration of the mechanisms, which mount the scoop unit 82. Althoughnot shown, it is preferable to utilize a rigid bar 32 that wouldfunction as described in the first embodiment.

DETAILED DESCRIPTION OF A THIRD EMBODIMENT

Reference is next made to FIGS. 8 to 11, which show a third embodimentof the invention. The third embodiment differs from the previousembodiment in that a scoop track 130 is built into the Scoop Unit 132.

The scoop track 130 comprises a pair of U-shaped channels 134 havingtheir open ends facing each other, shown as cross section in FIG. 8. TheU-shaped channels 134 can be built into and form part of the radiallyouter vertical wall structure of the scoop unit 132.

The scoop track 130 mounts onto a track slider/pivot 136, which as shownis secured to and projects radially inwardly from the vertical sidewall138 of the scoop carrier 140.

As shown in FIG. 9, the two U-shaped channels 134 flare outwardly awayfrom each near the bottom of the scoop unit 132, so that the scoop unit132 can be moved against sidewall 138 and then downwardly for the trackslider/pivot 136 to enter the scoop track 130 formed by the two U-shapedchannels 134. As the scoop unit 132 continues to move downwardly, theuser pushes the handle 141 of the scoop unit 132 forward. This causesthe scoop portion 144 to pivot rearwardly, as shown in FIG. 10 at whichpoint the rear end of the scoop portion 144 rotates upwardly against aguide rail 142 mounted on the vertical sidewall 138 of the scoop carrier140, preventing further upward pivoting of the scoop portion 144.

At this time, the user can release the handle 141 and begin rotating thescoop unit 132 in the litter container 146 by using the post 148 on thescoop carrier 140.

As the scoop unit 132 begins to move, the force of the litter againstthe scoop portion 144 cause the scoop unit 132 to move backwards. Theupper and rear portion of the scoop portion 144 slides rearwards alongthe guide rail 142 until it reaches a stop member 152 that preventsfurther rearward movement. The scoop unit 132 is now in its finalscooping position, as shown in FIG. 11.

After the scoop portion 144 has collected waste, the scoop unit 132 canbe removed. As the handle 141 on the scoop unit 132 is pulled upward,the leading edge portion 154 of the scoop portion 144 begins to moveforward and upward thus retaining captured waste in the scoop portion144.

In this embodiment a rigid bar 32 is not shown in order to simplify theillustration of the mechanisms. Although not shown, it is preferable toutilize a rigid bar 32 that would function as described in the firstembodiment.

DETAILED DESCRIPTION OF A FOURTH EMBODIMENT

In the embodiments previously described the mounting mechanisms not onlycause the scoop to be removed in a forward and upward movement, but alsothese mechanisms also cause the scoop to change orientation, as thescoop unit is inserted and removed from the litter container. Inscooping position, the scoop is in more of a vertical orientation. Asdiscussed previously, this vertical orientation means less surface areaof the scoop contacts the litter in a plane at right angles to thedirection of rotary movement of the scoop. Less surface area results ina smaller wave in front of the scoop meaning waste more readily flowsinto the scoop. However, if desired, a scoop that does not changeorientation as it is inserted and removed can be used. In this versionmore surface area of the scoop will contact the litter, therefore thisversion is not preferred.

Reference is made to FIGS. 12 and 13, which show a straight track 170,molded into the scoop carrier 172. A rectangular track slider 174 isbuilt into the side of the Scoop Unit 176 and fits into the straighttrack 170. Both Figures show the scoop unit 176 as cutaway to reveal theportion of the scoop unit 176 which is adjacent to the scoop carrier172.

FIG. 12 shows the scoop unit 176 as the track slider 174 is about to beinserted into the straight track 170. The person using the littercontainer 182 inserts the scoop unit 176 onto the straight track 170using the handle 178 of the scoop unit 176. The scoop unit 176 is pusheddown (the track slider 174 moving downward in the straight track 70)until the scoop portion 180 reaches the surface of the litter. At thispoint the user can begin to rotate the scoop unit 176 within the littercontainer 182 using the post 184 that is attached to the top of thescoop carrier 172. The force of the litter against the scoop portion 180causes the scoop unit 176 to move rearward and down the straight track170 until the track slider 174 comes to rest against a stop piece 186that protrudes outwardly into the middle of straight track 170.

FIG. 13 shows the Scoop Unit 176 in scooping position where the trackslider 174 has come to rest against the stop piece 186.

After the scoop portion 180 has captured waste in the litter container182, the scoop unit 176 is removed by utilizing the handle 178 to pullthe scoop unit 176 and track slider 174 out of the straight track 170.The scoop portion 180 moves forward against the litter and upward thusretaining the captured waste in the scoop portion 180.

In this embodiment a rigid bar 32 is not shown in order to simplify theillustration of the mechanisms. Although not shown, it is preferable toutilize a rigid bar 32 that would function as described in the firstembodiment.

DETAILED DESCRIPTION OF A FIFTH EMBODIMENT

Scoops work by having gaps, holes or slats which are intended to belarge enough to let litter granules pass through, but small enough tocapture and hold waste. A scoop with smaller perforations cleans better,but the trade off is that it takes longer for the litter to pass throughthe smaller perforations. It takes longer to clean the litter box, andthis is less convenient for the person doing the scooping. Most scoopsare designed to clean with some degree of speed. Therefore, it is commonfor small bits of waste to pass through the scoop. The result is alitter box that looks unclean and stays unclean until the entirecontents of the litter box are changed. FIGS. 14 through 16 refer to adevice for resizing the perforations in a scoop to enable a second gradeof cleaning. The first stage of cleaning is done with the standard sizedperforations. The second stage would be done utilizing a scoop changepiece to create smaller sized perforations, which would enable a morethorough cleaning of the litter container.

As shown in FIG. 14 the scoop unit 202 is modified with a scoop changepiece 200. The scoop change piece 200 is shown detached from the scoopunit 202.

The scoop change piece 200 made of flexible plastic and is shaped tomatch and to lay on the inside surface of the scoop portion 204. Thescoop change piece 200 has perforations 206 that are much smaller thanthose on the scoop portion 204. These small perforations 206 on thescoop change piece 200 are able to retain waste that would have passedthrough the perforations 206 on the scoop portion 204. Granules oflitter that are able to pass through the scoop change piece 200 alsopass through the scoop portion 204. When the scoop change piece 200 isin position on the scoop portion 204, and passes through the litter, theflexible plastic of the scoop change piece 200 easily deforms to layflush against the scoop portion 204.

Two hinges 208 connect the scoop portion 204 to the scoop change piece200. The hinges 208 are located on each upper end of the scoop portion204 and allow the scoop change piece 200 to be rotated upward such thatthe lower edge 210 of the scoop change piece 200 can be docked under acatch member 212 that is molded into the handle 114 of the scoop unit202.

In this embodiment the scoop change piece 200 is built into the scoopunit 202. If desired the scoop change piece 200 may be made as adisposable scoop change piece 168 as shown in FIGS. 15 and 16. Thedisposable scoop change piece 168 is designed to be inserted into thescoop unit 202, used, and then discarded.

FIG. 15 shows a disposable scoop change piece with circularperforations, while FIG. 16 shows a disposable scoop change piece withslotted perforations.

DETAILED DESCRIPTION OF A SIXTH EMBODIMENT

FIG. 17 through 20 refer to a handheld scoop 250 that is able to resizeits perforations to enable a coarse and a fine level of cleaning. Theparts of this scoop will next be described.

As shown in the figures the scoop portion 252 consists of two plasticsieves. Each sieve is designed in a grid pattern with square openings.Each opening is 1 centimeter by 1 centimeter. The width of the plasticgrid work is 2 centimeters.

The top sieve 256 has a length and width approximately 7 mm shorter thenthose dimensions of the bottom sieve 258. The thickness of the top sieve256 is approximately 1.5 mm. Molded on an end of the sieve is a upperbridging portion 260 which extends outwardly at the same plane as thetop sieve 256. The upper bridging portion 260 is 3 cm in length andtapers inwardly at its end. The upper surface of the upper bridgingportion 260 contains a thumb-operated post 262, the operation of whichwill be described later.

Molded on the bottom of the upper bridging portion 260 is a slide member264 that protrudes downwardly ⅖ cm. The slide member 264 is rectangularin shape and approximately 1 cm in length. On either side of the slidemember 264, at the bottom center, are outwardly protruding bumps 266,the purpose of which will be later described. The slide member 264 ismolded at a 45 degree angle relative to the grid work of the top sieve256 as shown in FIG. 19.

The bottom sieve 258 has dimensions approximately 10 cm by 10 cm. As thebottom sieve 258 is the load-bearing portion of the scoop 250, it isapproximately 6 mm thick. Although not shown in the figures, the twoside edges of the bottom sieve 258 will normally have molded upwardlyprotruding sidewalls the purpose of which is to keep captured waste fromfalling out of the scoop 250. The bottom sieve 258 has a lower bridgingportion 270 that extends outwardly and tapers to become a handle 272.The lower bridging portion 270 contains a channel 274 that is ⅖ cm deepand shaped to accept and contain the slide member 264. The channel 274is 1.607 cm in length and is molded at a 45 degree angle relative to thegrid work of the bottom sieve 258. The channel 274 also contains agroove 276 on either side near its the bottom such that the slide member264 will snap fit into the channel 274 when the bumps 266 enter thegroove 276. The grooves 276 also contain a set of two indentations 278on each side such that the slide member 264 will snap securely at eachindentation 278. The two sets of indentations will correspond toposition 1 and to position 2. A detailed transparent view of the slidemember 264 and channel 274 is shown in FIG. 18.

FIG. 19 shows an overhead exploded view of both the top sieve 256 andthe bottom sieve 258 showing the placement of the channel 274 and theslide member 264.

As shown in FIG. 17, in normal operation the top sieve 256 lays directlyon top of the bottom sieve 258. This is position 1. In position 1 theapparent size of the openings of the scoop is 1 cm×1 cm, whichcorresponds to stage 1 or a coarse level of scooping.

FIG. 18 shows the mechanism which connects the two sieves together. Thetwo sieves are connected together by the slide member 264, which is snapfit into the channel 274. When the bumps 266 on the slide member 264 aresecured in the indentations 278 corresponding to position 1, theopenings and plastic portions of each sieve's grid work match oneanother. In position 1 the apparent size of the of the openings of thescoop is 1 cm×1 cm, which corresponds to stage 1 or a coarse level ofscooping.

Next described is how the scoop is altered to present a second stage ofcleaning.

The thumb post 262 of the top sieve 256 is used to move the slide member264 in the channel 274 rearwards and sideways until the bumps 266 snapinto the two indentations 278 corresponding to position 2. This movementalso slides the top sieve 256 rearwardly and sideways by approximately0.607 centimeters. When this occurs the “apparent” number of squareperforations of the scoop portion 252 as viewed from above increases byfour times, while the apparent size of the perforations decrease byapproximately fourfold. FIG. 20 shows the scoop 250 with the top sieve256 in position 2 as viewed from above.

The scoop can now be used to provide a second level of cleaning, whichis much finer then the first level of cleaning.

DETAILED DESCRIPTION OF A SEVENTH EMBODIMENT

Many cat owners desire a cover for their litter box. A covered litterbox provides several benefits. A cover helps contain the odor in thelitter box. Some cat owners believe that their cats desire the privacyof a cover when they defecate. A cover also helps to hide the dirtycontents of the litter box from view. A cover also helps keep litterfrom being kicked out of the litter box by the cat. One of the majordisadvantages of a cover is that it must be removed in order to scoopout the waste from the litter box, and then replaced after scooping iscompleted. This embodiment provides a mechanism where scooping of thelitter box is provided by rotating the cover, as it sits atop the litterbox.

The relevant parts of the cover and litter container will now bedescribed. Reference is made to FIGS. 21 to 24. FIG. 21 shows the littercontainer 300 with the scoop unit 302 mounted on the sidewall slider304, and in scooping position. Scoop unit 302 and sidewall slider 304are of substantially the same design as in FIGS. 1 to 4A. The sidewallslider 304 is mounted on the container sidewall 306 of the container300. The interior diameter of the container sidewall 306 at its top isapproximately 19 inches. The container sidewall 306 includes anoutwardly extending lip 308 as shown. The sidewall slider 304 mounts onthe container sidewall 306 and over the extending lip 308. The top wall310 of the sidewall slider 304, which extends horizontally over theextending lip 308, is approximately 10 inches in length. The sidewallslider 304 has a cover-locking tab 312 molded onto its top horizontalsurface at its trailing end 314, in reference to the direction thesidewall slider 304 is normally rotated when scooping. The cover-lockingtab 312 extends upward approximately ⅔ inch and then rearwardly,extending approximately ¾ inch past the end of the sidewall slider. Thepurpose of the cover-locking tab 312 is to accept the rim 316 of thecover 318 as will later be described.

FIGS. 22 to 24 show the cover 318 for the litter container 300. Thecover 318 includes a circular sidewall 320 approximately 8 inches inheight. The cover 318 also includes a horizontal top wall 322 that ismolded to the top of the circular sidewall 320. The diameter of thecircular sidewall 320 is approximately 17-¾ inches at the bottom.Extending outwardly from the bottom of the cover 318 is a horizontallyprotruding rim 316 that extends outwardly by approximately 1 inch. Theprotruding rim 316 includes a vertical wall 326 that extends downwardly,from the edge of the protruding rim 316, by a distance of approximately¾ inch. One function of the protruding rim 316 is for mounting andsupporting the cover 318 in position on top of the litter container 300,as will later be described. The protruding rim 316 sits on top of theextending lip 308 of the litter container 300.

The protruding rim 316 does not run continuously around the circularsidewall 320 of the cover 318. The protruding rim 316 has a break thatcorresponds to, and is part of, an opening 328 cut out from the side ofthe circular sidewall 320. This opening 328 is approximately 7 incheshigh and is used as an entry and exit point for a cat to get in and outof the litter container 300, when the cover 318 is mounted on top of thelitter container 300. The break, or width of the opening 328, in theprotruding rim 316 is approximately 12 inches long, which isapproximately 2 inches longer than the top of the sidewall slider 304.

FIG. 24 shows a portion of the protruding rim 316 of the rear of thecover 318, opposite the opening 328, which is the front of the cover318. As shown, a horizontal cover-securing member or flange 330 extendshorizontally and inwardly from the vertical wall 326 of the protrudingrim 316. This cover-securing member 330 runs approximately 4 inches longalong the vertical wall 326 of the protruding rim 316 and extendsinwardly by approximately ¼ inch. Together, the protruding rim 316,vertical wall 326 and horizontal cover-securing member 330 create ajoint 332. This joint 332 helps secure the cover 318 on the littercontainer 300 as will next be described.

In normal use, and for scooping, the cover 318 is mounted on top of thelitter container 300. To mount the cover 318, the cover 318 is firstoriented above the litter container 300 such that the opening 328 of thecover 318 corresponds to, and is held slightly above, the sidewallslider 304. The joint 332 of the cover 318 is lowered and moved radiallyover the extending lip 308 of the litter container 300. The front of thecover 318 is then lowered so that the rim 316 of the cover 318 rests onthe extending lip 308 of the litter container 300. As the front of thecover 318 is lowered the opening 328 of the cover 318 lowers over thesidewall slider 304 and the cover-locking tab 312 of the sidewall slider304. As the cover 318 is mounted on the litter container 300, thevertical wall 326 of the rim 316 extends downwardly and over theextending lip 308 of the container. The snug fit of the vertical wall326 over the extending lip 308 ensures the cover 318 will not havehorizontal motion relative to the litter container 300.

To further secure the cover 318 to the litter container 300, the cover318 may be rotated slightly clockwise, such that the leading edge 334 ofthe horizontal portion of the rim 316 of the cover 318 slides under thecover-locking tab 312 of the sidewall slider 304. At this point verticalupward motion of the cover 318 is constrained by the cover-locking tab312 and by the joint 332, which has received the extending lip 308 ofthe litter container 300. Horizontal motion of the cover 318 atop thelitter container 300 is constrained by the vertical wall 326, which nowextends downwardly over the extending lip 308 of the litter container300. The cover 318, however, may be rotated in place on top of thelitter container 300.

Next described is how the cover is used to rotate the scoop unit 302.

Once the cover 318 has been mounted on the litter container 300, thescoop unit 302 is then inserted through the opening 328 of the cover 318and mounted onto the sidewall slider 304. The cover 318 is then graspedby the user and rotated clockwise, which corresponds to the directionthe scoop unit 302 is normally rotated for scooping. (A handle can beplaced on cover 318 if desired, or the cover can simply be gripped inany desired way.) As the cover 318 is rotated, the leading edge 334 ofthe rim 316 of the cover 318 abuts against the trailing end 314 of thesidewall slider 304 and pushes the sidewall slider 304 along thecontainer sidewall 306. The scoop unit 302 moves with the sidewallslider 304 and moves through the litter in the litter container 300 andcaptures waste. The cover 318 needs to be rotated by 360 degrees atleast once to cause the scoop unit 302 to pass through all the litter inthe litter container 300. The user may then stop rotating the cover 318.The scoop unit 302 can now be removed from the sidewall slider 304 andtaken out through the opening 328 of the cover 318. Waste that has beencaptured by the scoop unit 302 may now be disposed of.

The foregoing discussions and embodiments are presented as illustrativeand should not be taken as limiting. Other variations within the spiritand scope of this invention are possible and will present themselves tothose skilled in the art.

1. A circular litter container comprising: (a) a sidewall; (b) a scoopholder mounted on said sidewall for travel in a direction of travelaround said sidewall; (c) a scoop; (d) a mounting mechanism forremovably mounting said scoop on said scoop holder; (e) said mountingmechanism comprising cooperating mounting means on said scoop and saidscoop holder for said scoop to have an operating position in which saidscoop is oriented at a first angle relative to said direction of travelin which said scoop may be rotated through litter in said containerwhile minimizing formation of a wave of litter piled in front of saidscoop; (f) said cooperating mounting means including a guide such thatas said scoop is removed from said scoop holder, the orientation of saidscoop is redirected to a second angle nearer to the horizontal than saidfirst angle, whereby to help retain collected waste on said scoop; and(g) said scoop including a rear portion in said cooperating mountingmeans including a plug and socket removably connecting said rear portionof said scoop to said scoop holder.
 2. A litter container according toclaim 1 wherein said plug and socket means includes a substantiallycircular socket mounted on said scoop holder and a substantiallycircular plug mounted on said scoop, said plug being rotatable in saidsocket.
 3. A littler container according to claim 2 wherein said scoophas a front portion and said cooperating mounting means include aremovable connection between said front portion of said scoop and saidscoop holder, whereby said front portion of said scoop may be liftedupwardly relative to said scoop holder.
 4. A circular litter containercomprising: (a) a sidewall; (b) a scoop holder mounted on said sidewallfor travel in a direction of travel around said sidewall; (c) a scoop;(d) a mounting mechanism for removably mounting said scoop on said scoopholder; (e) said mounting mechanism comprising cooperating mountingmeans on said scoop and said scoop holder for said scoop to have anoperating position in which said scoop is oriented at a first anglerelative to said direction of travel in which said scoop may be rotatedthrough litter in said container while minimizing formation of a wave oflitter piled in front of said scoop; (f) said cooperating mounting meansincluding a guide such that as said scoop is removed from said scoopholder, the orientation of said scoop is redirected to a second anglenearer to the horizontal than said first angle, whereby to help retaincollected waste on said scoop; and (g) said cooperating mounting meanscomprising a track associated with one of said scoop and said scoopholder, and a guide piece associated with the other of said scoop andsaid scoop holder and movable within said track.
 5. A litter containeraccording to claim 4 wherein said track is curved.
 6. A circular littercontainer comprising: (a) a sidewall; (b) a scoop holder mounted on saidsidewall for travel in a direction of travel around said sidewall; (c) ascoop; (d) a mounting mechanism for removably mounting said scoop onsaid scoop holder; (e) said mounting mechanism comprising cooperatingmounting means on said scoop and said scoop holder for said scoop tohave an operating position in which said scoop is oriented at a firstangle relative to said direction of travel in which said scoop may berotated through litter in said container while minimizing formation of awave of litter piled in front of said scoop; (f) said cooperatingmounting means including a guide such that as said scoop is removed fromsaid scoop holder, the orientation of said scoop is redirected to asecond angle nearer to the horizontal than said first angle, whereby tohelp retain collected waste on said scoop; and (g) said container havinga bottom and said scoop holder including a scraper bar mounted to scrapesaid bottom as said scoop holder is rotated in said container.
 7. Acircular litter container comprising a bottom, a sidewall encirclingsaid bottom, a scoop holder mounted on said sidewall for travel aroundsaid sidewall, a scoop removably mounted in said scoop holder, and ascraper connected to said scoop holder for scraping said bottom of saidcontainer.
 8. A litter container according to claim 7 wherein saidscraper is pivotally connected to said bottom of said container forrotary movement about said container.
 9. A circular litter containerhaving a circular sidewall having an upper rim, a scoop holder mountedin said container for rotary movement in said container, a scoopremovably mounted in said scoop holder, a cover removably mounted onsaid rim and rotatable on said rim, said cover having an openingtherein, and connecting means for disengagably connecting said cover andsaid scoop holder such that rotation of said cover will rotate saidscoop holder within said container.
 10. A litter container according toclaim 9 wherein said opening in said cover is adjacent said scoopholder.
 11. A litter container according to claim 10 and having abottom, and wherein said scoop holder includes a scraper bar forscraping said bottom.
 12. A litter container according to claim 11 andincluding cooperating means associated with said scoop and said scoopholder for redirecting the orientation of said scoop from a first angleto a second angle when said scoop is removed from said container, saidsecond angle being closer to the horizontal than said first angle.
 13. Acircular litter container comprising: (a) a sidewall; (b) a scoop holdermounted on said sidewall for travel in a direction of travel around saidsidewall; (c) a scoop; (d) a mounting mechanism for removably mountingsaid scoop on said scoop holder; (e) said mounting mechanism comprisingcooperating mounting means on said scoop and said scoop holder for saidscoop to have an operating position in which said scoop is oriented at afirst angle relative to said direction of travel in which said scoop maybe rotated through litter in said container while minimizing formationof a wave of litter piled in front of said scoop; (f) said cooperatingmounting means including a guide such that as said scoop is removed fromsaid scoop holder, the orientation of said scoop is redirected to asecond angle nearer to the horizontal then said first angle, whereby tohelp retain collected waste on said scoop; and (g) said scoop includinga first sieve having openings of a predetermined size, and furtherincluding a second sieve attachable to said first sieve and adapted tocover said first sieve creating a finer screen for litter than either ofsaid first and second sieves separately.